It’s the action of informing your Google Ads account that a user that came from one of your Goolge campaigns did an action that is valuable to your business.
Based on the conversion information that you feed Google with, you can optimize your campaigns, targeted keywords, and adjust your bids.
Every aspect of your campaign’s performances is affected by the data created and collected by Google Ads and Google Analytics tag.
Because you can’t place your Google Analytics tag on the offer “thank you” page, Google doesn’t receive the conversion signals needed to optimize campaigns for ROI.
This infographic outlines how the data is passing from one touch point to another and back to Google Ads.
When the flow is completed, Google Ads can finally take into consideration the complete data-set and factor the metrics into the marketer's QualityScore.
You will be able to take advantage of all optimization features Google offers to marketers.